This application relates to a scroll compressor, wherein one of the two scroll members is formed of a significantly harder material than the other such that run-in can occur at start-up of the scroll compressor.
Scroll compressors are known, and are becoming widely utilized in fluid compression applications. In a typical scroll compressor, one scroll member has a base and a generally spiral wrap extending from its base. The generally spiral wrap of this scroll member interfits with a generally spiral wrap of a second scroll member. The wraps interfit to define compression chambers. One of the two scroll members is caused to orbit relative to the other, and as the orbiting movement occurs, the size of the compression chambers decrease and an entrapped fluid is compressed.
One challenge with scroll compressor designs is the creation of a separating force between the two scroll members. As the fluid is compressed, the pressure within the compression chambers increases, and tends to force the two scroll members away from each other. To address this, it is typical that a force is applied behind one of the two scroll members tending to bias it toward the other.
Thus, one of the two scroll members is typically capable of some limited axial movement toward the other.
In addition, it is important for there to be tight tolerances, and that the tip of the spiral wrap of one scroll member is close to the base of the opposed scroll member. However, due to tolerances, etc., it is often the case that some of the scroll wrap may be spaced from the opposed base.
Also, the actual shape of a scroll member in operation may change significantly from the machined shape. This can occur due to mechanical stresses, thermal stresses, and the internal pressures.
It is known to form the scroll compressor members of various materials.